If what you are saying is true, then it's phone apps (games) driving this revenue. In that case, it seems to me that one should actually buy Apple stock. Becaus

If what you are saying is true, then it's phone apps (games) driving this revenue. In that case, it seems to me that one should actually buy Apple stock. Because phone apps will only spend this kind of money on Facebook ads if they are able to generate RoI in the app store via in-app purchases. And Apple gets a 30% cut of that without doing anything. So Apple must be making as much revenue as Facebook from this phenomenon.